The invention concerns a method of delivering data streams in a network comprising devices connected to the network via adapters, a system for delivering data streams, where the system comprises a network of devices attached to the network via adapters, and a controller for a network of devices in which the devices are attached to the network via an adapter.
It is known to form a local area network, or LAN, by coupling or connecting a selection of devices to each other for the purposes of communication. Examples of devices which may be connected or coupled to each other include computers, both desktop and laptop, printers, electronic devices generally which process information, and also hand held devices such as mobile phones, tablet devices and personal assistants. In particular such a network can be established in a home environment and includes personal computers, laptops, video recorders, DVD players, television set top boxes and other devices which process information which is of use to the persons residing in the home. As is known by the skilled person, sometimes devices in a network are known as nodes.
The installation of a physical network between devices can be complex and require sophisticated knowledge and skills. Additionally, sometimes it is neither appropriate nor desirable to provide additional cabling to connect up or couple devices in a network. In such a case a network can be set up using an existing shared network, such as a power line network, a network using existing coaxial or hybrid fiber-coaxial cables, for example a DOCSIS network, or a bus network, if any of these is already present in the physical locality where the network of devices is required. Power line networks are described, for example, in Medium Access Control for Power Line Communications: An Overview of the IEEE 1901 and ITU-T G.hn Standards, by Md. Mustafizur Rahman et al., IEEE Communications Magazine, July 2011, pp. 183-191.
A shared network has a limited physical capacity and will at any one time have a limited bandwidth due to the signals it is carrying. Bandwidth cannot be exceeded, therefore when devices that are attached to such a shared physical network attempt to deliver data to each other within the network, and there is insufficient bandwidth in the shared segments of the network, delivery of the signals is disrupted.
This problem can be overcome by prioritisation, for example by using DiffServ, as is known in the art, however there are several different schedules of prioritisation and in the event of a local area network constructed from different devices it may be that the different devices use different prioritisation schedules from each other, or in some cases use none at all.
Further to this, however, in such a shared network devices are connected to the network via adapters. Adapters are relatively unsophisticated devices which may or not have the ability to apply or enforce prioritisation of data streams.
Therefore it is a problem to ensure signal delivery in a local area network.